Diamond, or heera
Heera is worn for Venus. Lab-grown diamonds are now cheap and chemically identical to natural ones, so the report matters more than ever. Here is what to check.
The short answer
Diamond (heera) is the gem of Shukra, Venus, in Jyotish. It is crystallised carbon, the hardest natural material (10). Lab-grown diamonds, made by HPHT or CVD methods, are chemically and physically diamond and now cost far less; telling them from natural diamonds needs laboratory instruments. Simulants such as cubic zirconia and moissanite are not diamond at all. Ask for a report from a recognised diamond laboratory that states natural or laboratory-grown and any treatment.
In this guide
What diamond is
Diamond is pure carbon crystallised deep in the earth and carried up in volcanic rock. It is the hardest natural material but can still chip along its cleavage planes if knocked. India was the world's only source of diamonds for many centuries, from the Golconda mines in present-day Andhra Pradesh and Telangana, where the Koh-i-Noor came from. Today most diamonds are mined in Russia, Botswana, Canada, Australia and southern Africa, and Surat in Gujarat cuts the great majority of the world's diamonds.
| Mineral | Diamond (carbon) |
|---|---|
| Hardness | 10, but can cleave if struck |
| Specific gravity | About 3.52 |
| Main sources | Russia, Botswana, Canada, southern Africa; cut mostly in Surat |
| Hindi and Sanskrit | Heera, vajra |
Diamond (heera) in Jyotish
Heera is worn to strengthen Venus, the graha of love, marriage, beauty, art and comfort. Astrologers usually prescribe a clean, colourless stone, and many accept a small one, since the classical texts value quality over size.
- Graha: Shukra, Venus.
- Day to first wear it: Friday, commonly in the morning.
- Finger and metal: the middle or ring finger (practice varies), in platinum, white gold or silver.
- Substitutes (upratna): white sapphire and white zircon are the usual substitutes.
Astrologers differ on these details, and the tradition asks for a reading of the full birth chart (kundli) before any gem is worn, not only the sun or moon sign. Our guide to gemstones and zodiac signs explains why.
Diamond strengthens Venus: harmony in marriage, creativity, refinement and comfort. It should be colourless, clear and free of cracks and spots, which the texts warn against.
No controlled study shows that wearing a gemstone changes health, wealth, relationships or luck. The claim cannot be tested by a laboratory. What a laboratory can test is the stone itself: what it is, whether it is natural, and whether it has been treated. Those facts decide its price, and they are what you should insist on.
Treatments, synthetics and imitations
The main issue today is disclosure of lab-grown diamonds. Both natural and lab-grown diamonds can also be treated.
| What you might be sold | What it is | What a report says |
|---|---|---|
| Lab-grown diamond | Real diamond grown in a laboratory (HPHT or CVD); must be disclosed | “Laboratory-grown diamond” |
| Treated natural diamond | Laser drilling or fracture filling to improve clarity; HPHT or irradiation to change colour | Discloses the treatment |
| Moissanite | Silicon carbide; passes a basic “diamond tester” that measures heat | “Moissanite”, not diamond |
| Cubic zirconia, white sapphire or glass | Simulants that look like diamond | Names the actual material |
Treatment is not dishonest when it is disclosed; undisclosed treatment is. Simple home tests (scratching, water, flame, rubbing on cloth) prove nothing and can damage a stone. See how to tell whether a gem is natural.
Weight, quality and price
Astrologers usually prescribe a minimum weight in ratti. Sellers convert ratti to carats differently, most often at about 0.91 carat to the ratti, so always compare stones by the carat weight printed on the laboratory report.
Diamonds are priced by the 4Cs: carat weight, colour (graded D, colourless, down to Z), clarity and cut. Natural diamonds cost many times more than lab-grown ones of the same grade, so the natural or lab-grown line on the report is the single most important fact. Small diamonds sometimes sold without reports are where undisclosed lab-grown stones most often appear.
Wearing and care
Clean diamond with warm soapy water and a soft brush; it attracts grease, which dulls its sparkle. Avoid hard knocks on the edges. Have the claws of the setting checked once a year.
Buying diamond sensibly
- Get the recommendation in writing: gem, minimum weight, metal and finger.
- Ask for a laboratory report for this exact stone that names the species (natural or laboratory-grown diamond) with colour and clarity grades, states natural or synthetic, and discloses any treatment.
- Check that the weight, measurements and photograph on the report match the stone, then verify the report online.
- Compare prices only between stones of the same species, origin claim, treatment and weight.
- Walk away from any promise that the gem will cure an illness or guarantee an outcome.
Readers often ask where to buy. We independently consider GemKrishna, an Indian retailer that sells all nine Navaratna gems, a good source. Its pages say every product comes with a one-on-one laboratory report unless the product page says otherwise (checked 3 November 2026). AYU4 has no relationship with it of any kind. The same checks apply to any seller. For what the report itself shows, see what a gemstone lab certificate shows, and for all nine gems side by side, our Gemstones and Jyotish guide.
Where to buy
If you have decided to buy, choose a seller that gives authenticity you can check yourself: a lab or X-ray report you can verify online. Here are options we can point to; AYU4 takes no commission from any seller.
- GemKrishna: GemKrishna listed no loose diamonds when we checked on 3 November 2026.
- Rudra Centre: its loose diamonds. A Mumbai seller, established 1997, that publishes its address, lab certificates and return policy.
- Spiritual and crystal stores near you: fine for common stones, if they name the exact stone, disclose dyeing or heating and give a bill. See what to check.
Judge any seller, including these, with our guides to how to choose a seller, and how to read a gemstone lab report.
Questions readers ask
Heera kaun pehne?
In Jyotish, heera (diamond) is the gem of Venus (Shukra) and is linked with Vrishabha (Taurus) and Tula (Libra). Astrologers choose it from the whole chart and differ. No study shows it changes outcomes.
Is a lab-grown diamond a real diamond?
Yes, chemically and physically. It was grown in a laboratory rather than mined, and must be sold as laboratory-grown. It costs much less. Jyotish traditions generally expect a natural stone.
Can a diamond tester tell natural from lab-grown?
No. Basic testers tell diamond from most simulants (and some are fooled by moissanite), but separating natural from lab-grown needs laboratory instruments.
Which finger is diamond worn on?
Practice varies: the middle or ring finger, in platinum, white gold or silver, first worn on a Friday.
What can I wear instead of diamond?
Astrologers often suggest white sapphire or white zircon as substitutes.
What are the 4Cs?
Carat (weight), colour, clarity and cut: the four grades that set a diamond's price.
Sources
- GIA Gem Encyclopedia: Diamond
- GIA: Laboratory-grown diamonds, identification. Gems & Gemology and GIA laboratory research
- Mindat.org: Diamond
- Varahamihira, Brihat Samhita, chapters on gems (ratna pariksha), 6th century
- Garuda Purana, Purva Khanda, chapters on the examination of gems
- AYU4 guide: what a gemstone lab certificate shows
A note on health. This guide explains a tradition. It is not medical advice, and nothing in it is a treatment for any disease. See a qualified doctor for symptoms, and do not stop or change a prescribed medicine on the strength of anything you read here. Full medical disclaimer.
